Species identification in the North American cowbird: appropriate responses to abnormal song.

Abstract

Female cowbirds raised in auditory isolated from males responded to the songs of male cowbirds with copulatory postures. The songs of males reared in isolated were more effective in eliciting the posture than the songs of normally reared males. The females did not respond to the songs of other species. These results indicate one mechanism of species identification for this parasitic species.